What is this medal?

What is this medal?

My father has a medal that we don't know anything about. It has a lion standing on it’s hind legs with a thistle at the 3, 6, 9 and 12 o’clock positions. From googling lion and thistle, I believe that this medal has a Scottish origin (but I could be wrong).

I know that my great grandfather had become friends with Sir Robert McAlpine while the railway line was being constructed between County Wexford and County Waterford here in Ireland. I’ve been told that Sir Robert asked my great grandfather (who was a retired R.I.C. Sgt.) to help out with the war effort by joining the Gretna Green police. My great grandfather left his family in Ireland for the duration of the WW1, and went to work in Scotland.

I've tried uploading a photo here, but it won't work.

Could this medal be from my great grandfather’s time in Scotland? Any information would be appreciated.